JP-A-2007-330083 discloses a power exchange system for performing an exchange of power between a home and an electric vehicle.
The home is equipped with a charger/discharger for charging/discharging a battery of the vehicle and a controller for controlling the charger/discharger. The controller controls the charger/discharger so that the vehicle battery can be charged at night when electricity is cheaper than during the day.
Further, the controller controls the charger/discharger so that the vehicle battery can be discharged to supply power to the home during a power outage or shortage. For the purpose of safety, when a user is absent, the controller prevents the charger/discharger from charging and discharging the vehicle battery. Further, the controller controls the charger/discharger based on the target energy for the battery and the remaining energy in the battery so that power consumption in electrical appliances in the home can be leveled out.
In the conventional system disclosed in JP-A-2007-330083, since the vehicle is not equipped with a controller for controlling the charge/discharge of the vehicle battery, it is impossible for the vehicle-side to cause the home-side to charge/discharge the vehicle battery in response to a charge/discharge request occurring in the vehicle-side.
Further, the conventional system cannot be used, if the home is not equipped with the controller.
That is, the conventional system can be used to charge/discharge the vehicle battery, only when the home is equipped with the controller and the charger/discharger. Therefore, the conventional system lacks versatility.